| 摘要 |
PROBLEM TO BE SOLVED: To provide a CATV system, which converts a frequency of a BS-IF signal into a broadcast frequency for a UHF band assigned to ground television broadcasting and transmits the converted signal to terminals, can more efficiently conduct the frequency conversion from the frequency of the BS-IF signal into the frequency for the UHF band. SOLUTION: The CATV system first applies frequency conversion to BS digital reception signals (BS-IF signals of 1st, 3rd, 13th and 15th channels) into channels A-D for the SHB band and then applies frequency conversion to the BS digital reception signals into frequencies of the UHF band not used for other television broadcast signals (channels K-N), and transmits the converted signals to transmission channels. Since the CATV system can use a SAW filter with an excellent characteristic for the frequency conversion from the BS-IF signals into the channels A-D and conduct the frequency conversion from the SHB band into the UHF band in a batch for the 4 consecutive channels, the CATV system can efficiently and economically be built up.
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